Hi folks,

Today we are going to try to explain as simple as possible what TWAIN is all about.

The need for a standard

Some time ago, one could operate a scanner by using the manufacturer’s software only.
That happened because, following a general pattern in software history, each producer attempted to provide its proprietary product standard at first.
But soon enough, the need for a unified standard emerged, so some important scanner manufacturers and software publishers gathered up to form a group meant to design and maintain a unique standard to allow any imaging software to operate their scanners.
The resulting protocol was called TWAIN, and the group that maintains and develops it is named “TWAIN Working Group.”

But what is TWAIN?

As explained in the previous blog article, TWAIN is a set of specifications, not a software (just as a side note, the TWAIN Working Group releases toolkits but only to provide vendors with assistance in achieving TWAIN compliance, nothing more).
By following these specifications, when developing the drivers, scanner manufacturers give users the chance to use their particular scanner with any image or document processing software.
So basically, TWAIN contains the blueprint of a bridge, having one end “fixed” on a unique, specific image-acquisition device and the other end “opened” to any imaging/processing software.

Controlling the scanning process

Regarding the user interface, it allows you to control the scanning process: define the B/W, grayscale or color mode (if applicable), define scanning resolution (expressed in dpi, “dots per inch”) or set the area of the flatbed glass that has to be scanned.
After the scan is done, the acquired image is transferred to the application you are using, so you can process it.
If you are using PaperScan you can apply

  • filters
  • image corrections and/or enhancements
  • color and tonal balance tuning
  • image and document editing
  • annotations
  • OCR
  • and so on,

then, finally, save your document in a format of your choice.

GdPicture.NET SDK, our flagship product, provides developers with support for both TWAIN and WIA to use for their applications.

The TWAIN protocol is being continuously improved, so there are many revisions/versions of TWAIN.
The current release is 2.2, as of 16 February 2012.
03/30/20 edit: the lastest version available is 2.4 from 11 December 2015.

This brief depiction intended only to highlight the bottom line about TWAIN.
Similarly, our next article will be about WIA.

See you next week!


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